Key Points:

Northland police are investigating the death of a man whose body was found lying on rocks at Shipwreck Bay, near Kaitaia, yesterday.

Whangarei police spokeswoman Sarah Kennett told NZPA a member of the public found the man about 10.30am.

The man was thought to be in his early 30s, from nearby Ahipara.

Ms Kennett said the man had been in the water overnight.

He was due to undergo a post mortem this afternoon in Auckland.

Police would not comment on whether there were any suspicious circumstances surrounding the man's death until after the post mortem, Ms Kennett said.